In recent years, as for a transmissive type liquid crystal display apparatus using a liquid crystal panel which is widely spread as a display apparatus of a television receiver etc., research and development for enlarging a liquid crystal display apparatus have been performed actively.
As a prior literature for realization of enlarging the liquid crystal display apparatus, a liquid crystal display apparatus is proposed in which a plurality of liquid crystal panels are joined together on the same plane and tiled so as to enlarge a liquid crystal panel, for example (Japanese Patent Application Publication No. H10-096911).
In the transmissive type liquid crystal display apparatus, it is necessary to provide a backlight for irradiating the liquid crystal panel with light from the rear side. For this reason, such liquid crystal display apparatuses can be classified roughly into a bottom backlight system and an edge light (side light) system, according to a structure of the backlight (Japanese Patent Application Publication No. 2001-266605).
In a small-sized liquid crystal display apparatus having a size of approximately 15 inches, the edge light system with which thickness of the backlight can be made thin is employed widely. For example, a backlight with a thickness of approximately 5 mm is realized and put into practical use.
However, in a backlight of the edge light system such as mentioned above, light is incident to a side edge (a side surface) of a light guide plate, and uniform light is emitted from an upper surface side of the light guide plate to the liquid crystal panel, so that a usage efficiency of the light is bad.
For this reason, when the backlight of a conventional side edge system illuminates a large-sized liquid crystal display apparatus having a size of 20 inches or more, for example, there is a disadvantage that the whole liquid crystal panel can not be illuminated uniformly with light of high brightness.
In other words, for example, when the backlight of the large-sized liquid crystal display apparatus is constructed by way of the edge light method, it is conceivable to use a light source of much higher brightness than a light source which is used for a conventional liquid crystal display apparatus with a size of approximately 15 inches. However, such a light source of high brightness does not exist at present.
Therefore, in order to attain high brightness of the large-sized liquid crystal display apparatus, there is only a way that a lot of (for example, three or more) fluorescence tubes are arranged at a side edge of the light guide plate, for securing a quantity of light. There is a limit in obtention of the brightness for displaying a television image. Incidentally, there is no description of a structure of the backlight in the Japanese Laid-open Patent No. H10-096911.
Moreover, when a lot of fluorescence tubes are arranged as the light source on the side edge of the light guide plate so that the light of the fluorescence tubes is taken into the light guide plate, an acrylic resin which forms the light guide plate becomes thick. Thus, when the backlight of a large-sized liquid crystal display apparatus is realized by the side edge, there is a disadvantage that its weight becomes very heavy.
Then, the present invention is invented in view of the points as described above, and provides a backlight suitable for the large-sized liquid crystal display apparatus, the backlight drive apparatus for driving such a backlight and the display apparatus arranged to have such a backlight.